Nano-Level Detection of Certain Beta-Blockers Based on Surface Plasmon Resonance Band of Silver Nanoparticles; Application to Content Uniformity Test

A simple, sensitive and cost effective method was developed and validated for the determination of some β-adrenergic blocking agents namely; carvedilol, labetalol hydrochloride, nebivolol hydrochloride and sotalol hydrochloride. The method was based on the ability of the cited drugs to induce the formation of silver nanoparticles (Ag-NPs) in the presence of polyvinyl pyrrolidone as a stabilizer. The intense surface plasmon resonance of the formed nanoparticles appeared at 420 nm, was utilized for the quantitative spectrophotometric determination of the beta-blockers. The linear concentration ranges were 0.05 - 1.6, 0.16 - 3.0, 0.2 - 2.5 and 0.10 - 2.0 μg mL^-1 for carvedilol, labetalol hydrochloride, nebivolol hydrochloride and sotalol hydrochloride respectively with limits of detection of 30, 53, 62 and 34 ng mL^-1, respectively. The commercial dosage forms containing the studied drugs were analyzed by the proposed method and the results were compared statistically with those obtained by the reported methods. The comparison revealed high precision and accuracy of the suggested method. Moreover, the method was extended to the content uniformity testing of commercial tablets dosage forms.